Composite article



Nov. 27, 1923. 1,475,764 L. T. FREDERICK COMPOSITE ARTICLE Filed May 12, 1919 wnmzssrzs: INVENTOR {GYM lauzlsfffieorick. mm. BY

ATTORNEY Patented Nov. 27, 1923.

UNITED STATES- PATENT OFFICE.

LOUIS '1. FREDERICK, 0F WILKINSBUBG,

PENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYL- VANIA.

COMPOSITE ARTICLE.

Applicatiqn filed May 12, 1919. Serial No. 296,588.

To all whomvlt may concern:

Be it known that I, LOUIS T. Fnnnnmox, a citizen of the United States, and a resident of Wilkinsbur in the county of Allegheny and State of ennsylvania, have invented a new and useful Improvement in Composite Articles, of which the following is a specification.

My invention relates to composite articles and it has, for its primary object, the provision of articles formed of fibrous material and a binder adapted to harden under the application of heat and pressure.

Heretofore, articles have been formed of fibrous material and a suitable binder in which the fibrous material has been employed in sheet form and cut or stacked to .form the shape of the article desired. The

binder employed has been of such nature that, when subjected to heat, it would harden and impart rigidity of form to the shaped sheets of fibrous material. Although articles formed in this manner are very satisfactory for a great variety of purposes, the method of forming them is open to some 0bjection because of the fact that the sheets of fibrous material are sometimes difii'cult'to handle in order to obtain the desired shape of the article.

For example, in the construction ,of stream-line tail pieces for motor generator sets which are employed in airplane work, the tail pieces have been formed by employing sheets of duck which were impregnated with a suitable binder and so cut that stacked layers of the material could be formed into an elongate body having a closed end of stream-line shape. In order to obtain the particular stream-line shape of this article, considerable difiiculty was met with in arriving at the particular method of cutting the material and stacking it to provide the stream-line contour.

One object of my invention, therefore, resides in a method of constructing articles, particularly nonlaniform articles, in such manner that the s ape of the article may be provided with little difi'iculty.

Referring to the drawings, I 1g. 1 is a side elevation of a supporting member or screen partially covered by paper pulp, illustrating the manner of forming a hollow body in aceordance with my invention;' Fig. 2 is a.

transverse sectional view of a mold in which the body may be subjected to heat and pres sure,and Fig. 3 is a perspective view of the finished body.

In ractism my invention, I may employ a pu p forme of any suitable materials, particularly those well known in paper manufacture. I prefer to employ, however, a pulp containing strong fibres and to shape an article of the pulp upon any suitable supporting member. The pulp may be so employed in a saturated form that the deposition of it upon the supportin be readily accomplished. he supporting member upon which the pulp may be deposited is preferably of the article desired and, after the pulp has been deposited thereon, it may be so subjected to slight pressure and to sufiicient heat that it shall be dried and compacted to suificient rigidity of form to permit of removing the supporting member. After the article has been thus formed, it may be impregnated with a suitable binder, such as a phenolic condensation product, and may then be subjected to further heat and pressure to compact the material and to harden the binder.

In forming an article, such as the stream line tail piece above mentioned, considerable difliculty may be avoided'in the manufacture thereof by forming the article of-pulp deposited upon a screen or other suitable supporting member and then removing it from the screen and impregnating it with a binder which may be subsequently hardened. A tail piece formed in this manner may not have as great mechanical strength as one formed of stacked sheets of fibrous material, but it will possess suflicient mechanical strength for the purpose for which it is intended.

In order to facilitate an understanding of my invention, the manner of forming a hollow body, closed at one end, is illustrated in the drawings, in Fig. 1 of which 1 indicates a supporting member formed of closemesh screen which is preferably out along its entire len h, as indicated at 2. Paper pulp 3, or pu p of other material, in a moist conditions, may be deposited upon the suporting member 1 to thus form the desired dy. The pulp 3 is shown as covering only a portion of the screen or supporting mem" member may her 1 in order to illustrate the manner of forming the body. After the pulp has been deposited upon the supporting member, it may be heated tothoroughly drive off its moisture. content and, if necessary, some pressure may be applied to compact the pulp sufliciently to permit of removing the supporting member 1. The removal of the supporting member 1 is facilitated by having it cut, as indicated at 2, whereby one of the cut edges may be depressed to diminish the diameter of the supporting member and facilitate releasing it from the compacted ul p A fter the formed pulp 3 has been removed from the supporting member 1, it may be impregnated with a suitable binder, such as a phenolic condensation product, and a core member 4 of suitable shape may be inserted in the im regnated ,body and the body disposed in a mold 5. Heat and pressure may be applied to the mold which, of course, has splits 6 and 7 of suitable shape to receive the body 3 and its core member 4. It should be noted that the pressure applied during the forming of the pulp to compact it sufiiciently to permit of the remove of its supporting member is only sufiicient to cause the adhesion of the fibrous particles. Further pressure is applied to the mold 5, together with heat, to thoroughly compact the material and to harden the binder to its substantially'insoluble and infusible state. If the body is then removed from the mold it presents the appearance of the article 8 shown in Fig. 3. A stream-line tail piece for motor-generator sets of airplanes has been employed by way of illustration but it will be apparent that articles of similar character may be constructed in substantially the same manner.

On account of the fact that the pulp may be readily impregnated and contains innumerable fibres, the pulp may be united into a very homogeneous and exceptionally rigid body by employing a phenolic condensation product as the binder. The fibres of the pulp are knitted together and, on account of the great number of engaging surfaces through the material, greater mechanical strength may be obtained than could be attained in an article formed of pulp in any other manner.

Furthermore. by employing pulp, articles, having shapes hard to obtain by employing sheet material, may be easily constructed. For example. articles which are so formed as to be almost completely enclosed may be readily formed by practising my invention. A container, such as a barrel, may be formed by depositing the pulp upon a screen in which only a small opening may remain in one of its ends. After the article has been thus formed, it may be impregnated with the binder and the pressure and 'heat to harden the binder and form a unitary ody may be ap lied after the manner disclosed in an app ication filed Oct. 8, 1917, by C. T. Allcutt, bearin Serial No. 195,262 and assi ned to the estinghouse Electric & Manu acturing Company.

As disclosed in the above mentioned aplication, a fusible core may be introduced mto the body, and heat and pressure may be applied by this means. The fusible core may comprise an alloy, such as Rose metal or Woods metal, which melts at a comparativel low temperature and will, therefore, not injure the pulp impregnated with the phenolic condensation product in the course of the application of the pressure to the core. Of course, the article must be disposed within a suitable casing and the fused core introduced into the article and pressure applied thereto together with suflicient heat to harden the phenolic condensation product. After the binder has been thoroughly hardened, the core may be drained from the article in substantially the same manner in which it was introduced into the article. An article, therefore, whichit is desired to construct with only a small opening in one part thereof, may be readily formed by employing the fusible core ina plying the pressure to compact the material:

It will be readily appreciated from the foregoing description that a wide variety of articles may be formed in accordance with my invention. The particular manner of forming the body desired may also be accomplished by practising various methods and I desire, therefore, not to be restricted to any particular shape of article or method of forming it except in so far as limitations may be imposed by the prior art of the appended claims.

I claim as my invention:

1. 'A method of manufacturing hollow l composite articles that comprises forming the article by depositing fibrous pulp upon a suitable supporting member, removing the member, impregnating the pulp with a phenolic condensation product, and subjecting the body thus formed to heat and pressure.

2. A method of manufacturing hollow composite articles that comprises forming pregnating the body with a phenolic condensation product and applying further heat nd pressure to harden the phenolic condensation product and compact the body.

4. A method of manufacturing hollow composite articles that comprises forming 5 an article of paper pulp, drying and compacting the pulp by applying heat and pressure thereto, impregnating the body thus formed with a phenolic condensation product and subjecting the body to heat and PIGS- sure to form a hard and unitary article.

In testimony whereof, I have hereunto subscribed my name this 30thday of April,

LOUIS T. FREDERICK. 

